Light-related adverse side-effects of drugs are now an important source of concern. In order that the mechanism underlying to such effects is recognized, an in-depth photochemical study must be carried out. ICH Q1B (The ICH rule Q1B defines the Irradiation dose for UV and white light) guideline is the harmonized effort to standardize photostability testing on new pharmaceutical drug substances and drug products. For companies developing or manufacturing pharmaceutical drugs, a robust photostability testing process is essential to ensure product quality and regulatory compliance.
Stability tests are an important step in the course of the development of new drugs and pharmaceutical substances. Photostability chambers are designed to carry out stability and shelf life studies on drug and drugs substances. These chambers are also known as Pharmaceutical Photostability Chamber. These chambers allow the photostability test in accordance with ICH guidelines. (The ICH rule Q1B defines the Irradiation dose for UV and white light). Photostability chambers are characterized by an ideal light, UV, temperature and humidity distribution.
Note: ICH stands for International Conference on Harmonization
Photostability Test
At first the actual substance without any modification is tested, after that the final product without any wrapping is tested. If the final product remains photostable, that is the changes caused by the light are negligible or acceptable or can be disregarded; the test is finished at this point.
If unacceptable changes occur those modify the chemical structure of the test product, actions can be taken for the light protection of the specimens. The examinations are carried out once again e.g. in the first step the specimens are tested in a direct wrapping (like blister wrapping or glass), for further steps in sales packaging.
If the light stability is achieved with the taken action, normally this is seen in the storage tips, e.g. store only in the dark.
With such photostability examinations it is tested, how far the mentioned products change their chemical characteristics by light irradiation
One of the most important requirements in Photostability Tests is the homogeneous irradiation of the specimens. For this reason, all the specimens have to be positioned at the same distance from the light source.